M. Fabius Quintilianus
... uta Latinis veteribus d plurimis in verbis adiectam ultimam, quod manifestum est etiam ex columna rostrata, quae est Duilio in foro posita;
And in Latin ancient writers ended a number of words with d, as may be seen on the column adorned with the beaks of ships, which was set up in the forum in honour of Duilius.
Reprinted by permission of the publishers and the Trustees of the Loeb Classical Library from M. Fabius Quintilianus: The Orator's Education (Volume I. Books 1-2), Loeb Classical Library Vol. 124, translated by Donald A. Russel, Cambridge, Mass.: Harvard University Press, © 2002, by the President and Fellows of Harvard College. The Loeb Classical Library ® is a registered trademark of the President and Fellows of Harvard College.